Overspeed governor



Nov. 18, 1958 H. L. GARDNER, JR 2,350,865

ovERsPEED GOVERNOR Filed Nov. so, 1954 Ninn-es@ INVENTOR. HORACEGARDNERJR.

2,860,865 Patented Nov. 18, 1958 United IStates Patent @thee 2,860,865 lovERsPEED GOVERNOR Horace L. Gardner, Jr., Wantagh, N. Y., assignor toFairchild Engine and Airplane Corporation, Hagerstown, Md., acorporation of Maryland Application November 30, 1954, Serial No.472,023 5 Claims. (Cl. 264-17) Vof rotation in a direction which wouldshift the actuator toward the operative position, except that -slidablemovement of the companion member is normally resisted by a spring.

With the above arrangement, the actuator is maintained'in theinoperative position bythe centrifugal force of rotation at allowablespeeds of rotation, however,

when the speed of ,rotation exceeds the predetermined limit, meansresisting the slidable movement of the companion member is renderedinoperative, permitting the companion memberto shift the actuator insuch fashion that the centrifugal force of rotation urges the actuatorin the opposite direction, namely toward the operative position, toactuate the control for the prime mover.

The overspeed governor -of the present invention yprovides a highlysatisfactory speed control device which may be readily mounted to therotary member whose speed is to be governed while at the same timeaffording a very simple, compact and inexpensive construction.

The present invention will be more fully understood by reference to thedetailed description which follows and to the accompanying drawings inwhich:

Figure 1 is Aa cross-sectional view of the presentoverspeedgovernor; .i

Figure .2 is a cross-sectional view taken on a plane perpendicular tothe view shown in Figure 1, but showing the actuator in a differentposition; and

Figure 3 is a perspective view of a collapsible cornponent of theoverspeed governor shown in Figures 1 and 2.

Referring to the drawing, the overspeed governor of the presentinvention comprises a body or housing 10 internally threaded at one end,as at 11, to permit the governor to be screwed on to the extreme end ofa shaft Whose speed is to be controlled. The axis of the overspeedgovernor is coaxial with the shaft whose speed is to be controlled, and-the common axis is represented by the reference character a.

The housing is formed with a cylindrical bore 12 which intersects theaxis a at right angles, and one end 12a of the bore 12 is of enlargeddiameter forming a shoulder 12b. The bore 12 receives a sleeve 14, andthe sleeve 14 is provided with an outwardly projecting annular rim 14aaround its outer periphery, which in the normal position of the sleeveis adapted toV abut against the shoulder 12b. The inner periphery of theend 12a of the bore 12 is threaded to receive a` threaded plug 15, andthe plug 15 contains a central opening to receive the sleeve member 14and to permit the. sleeve limited movement therein.

With the plug 15 in place, the movement of the sleeve 14 within the bore12 is limited in one direction by the engagement of the annularprojecting rim 14a with the shoulder 12b and would be limited in theother` direction by the end of the plug 15 were it not for a yieldable,collapsible wave washer or Belleville washer 16 vinterposed between'theplug and the rim 14a which normally maintains the rim 14a in contactwith the shoulder 12b.

An actuating pin 18 is slidably containedvwithin the sleeve 14, and theactuating pin 18 is normally urged by a compression spring 19 to aretracted or inoperative position, shown in Figure 1, wherein the headportion 20 of the pin is in contact with an'annular retaining ring A21.

The opposite end of the pin 18 extends through the end of the sleeve 14,and the pin is free to m-ove in the said sleeve against the pressure ofthe spring 19 to the position represented in Figure 2, at which positionthe pin 18 trips the pivotal `control lever 23, thereby shutting down orreducing the speed of the prime mover. The travel of the actuating pin18 in the operativev direction is limited by a shoulder 14b (Figure l)within the sleeve 14.

Referring to Figure 1, the center of gravity Vof the actuating pin 18 isrepresented by the reference character w, the center of gravity of thesleeve 14 by the reference character y, and the center of gravity of theassembly including the sleeve, the compression spring 19 and theactuating pin 18 by the reference character x. ln the normal position ofrest the center of gravity x of the pin and sleeve unit and the centerof gravity w of the actuating 'pin alone are on the opposite sides ofthe axis of rotation a. The position of the center of gravity w of thepin alone is such, therefore, that at allowable speeds of rotation thepin is urged by centrifugal force toward the inoperative position,represented in Figure l, maintaining the head 20 of the pin in contactwith the ring 21. The center of gravity x of the pin and sleeveassembly, however, is disposed` on the opposite side of the axis, withthe result that the effect of the centrifugal force is to urge theassembly, including the pin, in the opposite direction. The movement ofthe unit by the centrifugal force, however, is resisted by the wavewasher 16.

In the normal position of rest, the wave washer'16 is partiallycompressed and therefore resists any further deformation until adefinite force is reached, whereupon' the washer collapses in a quickand sudden motion almost instantly with the application of buta smalladditional increment of force. Thus, when the speed of rotation reachesthe point where the centrifugal force of the pin' and sleeve assembly iscapable of collapsing the ring washer 16, the resulting sliding movementof the sleeve 14 within the slot will cause the center of gravity w ofthe pin to be shifted to the opposite side of the axis a, therebyreversing the effect of the centrifugal 4force upon the pin 18 andsliding it against the compressive force of the spring 19 to theoperative position represented in' Figure 2. In this position, asmentioned above, the trip lever 23 will be within the path of travel ofthe operative end of the pin and will, therefore, be actuated to shutdown or reduce the speed of the prime mover.

It is evident that the pressure exerted on the wave washer 16 may becontrolled by threadably adjusting the plug 15 to regulate the value ofthe centrifugal force which will collapse the washer. This adjustment ofthe plug is facilitated by the slots 15a in the exposed end of the plugwhich receive a suitable key.

The present invention has been shown in a single preferred form and byway of example only, and obviously many modifications and variations maybe made therein without departing from the spirit of the invention. itis to be understood, therefore, that the invention is not to be limitedto any specified form or embodiment except insofar as such limitationsare set forth in the claims.

I claim:

1. A centrifugal governor for a rotary member comprising an actuatorslidably carried by the rotary member, yielding means for urging theactuator to an inoperative position, movable companion member carried bythe rotary member and engageable with said actuator, means formaintaining said companion member in a normal position, the relativepositions of the actuator in inoperative position and the movablecompanion member in normal position being such that the eiect of thecentrifugal force during rotation urges the actuator toward theinoperative position while the effect of the centrifugal force on thecompanion member urges the actuator toward operative position, andcollapsible means for resisting the slidable movement of the companionmember until a predetermined speed of rotation yis exceeded, whereuponthe resistance of the collapsible means is overcome suddenly, permittingthe companion member to shift the center of gravity of the actuator tothe opposite side of the axis of rotation of the governor, whereupon thecentrifugal force of rotation will urge the actuator to operativeposition.

2. A centrifugal governor for a rotary member comprising a sleeve memberslidably carried by the rotary member, registration means formaintaining said sleeve member in an inoperative position, an actuatorslidably accommodated within the sleeve member, yielding means forurging the actuator to an inoperative position, the effect of thecentrifugal force during rotation of the rtary member urging theactuator toward the inoperative position, while the effect of thecentrifugal force on the sleeve member urges the sleeve member and theactuator accommodated therein toward operative position, and means forresisting the slidable movement of the sleeve member until apredetermined speed of rotation is exceeded, whereupon' the resistingmeans is overcome, permitting the sleeve member to shift the center ofgravity of the actuator to the opposite side of the axis of rotation ofthe rotary member, whereupon the centrifugal force of rotation will urgethe actuator to operative position.

3. A centrifugal governor for a rotary member comprising a housingmounted to the rotary member, a sleeve member slidably received in thehousing, an actuator slidably movable within the sleeve between xedlimits,

spring means urging the actuator to a position wherein the center ofgravity of the actuator is so disposed with respect to the axis ofrotation of the housing that the centrifugal force of rotation urges theactuator toward inoperative position, stop means for the slidablesleeve, an'd a restraining means normally maintaining the sleeve memberin contact with said stop means, at which position the center of gravityof the actuator and sleeve assembly is disposed on the opposite side ofthe axis of rotation of the housing from the center of gravity of theactuator alone, the arrangement being such that at rotational speedsabove the allowable limit, the centrifugal force of the assembly willovercome the restraining means, thereby permitting the sleeve member toengage the actuator and shift the center of gravity of the actuator tothe opposite side of the axis of rotation, the centrifugal forcethereupon urging the actuator to the operative position.

4. A centrifugal governor as set forth in claim 3 wherein the springurging the actuator toward inoperative position is a compression springaccommodated within the sleeve member.

5. A centrifugal governor for a rotary member comprising a housingadapted to be mounted to the rotary member, an actuator slidablyreceived in the housing, a companion member slidably received in' thehousing and concentrically disposed with respect to the actuator, springmeans urging the actuator to a position wherein the center of gravity ofthe actuator is so disposed with respect to the axis of rotation of thehousing that the centrifugal force of rotation urges the actuator towardinoperative position, stop means for the slidable companion member, anda collapsible ring washer which normally urges the companion member intoContact with said stop means, in which position the center of gravity ofthe actuator and companion member assembly is disposed on' the oppositeside of the axis of rotation of the housing from the center of gravityof the actuator alone, the arrangement being such that at rotationalspeeds above the allowable limit, the centrifugal force of the assemblywill cause the ring washer to collapse, thereby permitting the companionmember to engage the actuator and shift the center of gravity of theactuator to the opposite side of the axis of rotation of the housing,the centrifugal force thereupon' urging the actuator to the operativeposition.

References Cited in the tile of this patent UNITED STATES PATENTS2,388,282 Otto Nov. 6, 1945 2,474,324 Ray June 28, 1949 2,666,572Pickels Jan. 19, 1954 2,691,516 Fischer Oct. 12, 1954

